Connector system for a rod-shaped two-ended discharge lamp

ABSTRACT

A connector system for a rod-shaped two-ended gas discharge lamp ( 12 ) with bases ( 20 ) disposed on the connector ends ( 16 ) of the discharge lamp ( 12 ) and with insert sockets ( 22 ) for receiving the bases ( 20 ) in a lamp housing ( 14 ). Each base ( 20 ) is provided with a contact pin ( 26 ) linked with a lamp electrode ( 36 ) with an insulating cylinder ( 28 ) surrounding the contact pin ( 26 ) while leaving a lateral connector opening ( 46 ) free. Each insert socket ( 22 ) is provided with a contact element ( 58 ) that can be detachably engaged with the corresponding contact pin ( 26 ) through the connector opening ( 46 ) of the pertaining base ( 20 ) and can be impinged upon with a high voltage. The insert socket is further provided with an insulating body ( 60 ) that carries the contact element ( 58 ) and covers the connector opening ( 46 ) in the connected state.

CROSS REFERENCE TO RELATED APPLICATION

This application is a national stage of PCT/EP00/09064 filed Sep. 16,2000 and based upon DE 199 55 979.1 filed Nov. 20, 1999 under theInternational Convention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a connector system for a rod-shaped two-endeddischarge lamp, in particular a mercury high pressure lamp or a mercurymedium pressure lamp, with two lamp bases provided at the connector endsof the discharge lamp and two insert sockets for receiving the lampbases mounted spaced apart from each other in a lamp housing.

2. Description of the Related Art

Taking advantage of their emission in the UV-range, mercury high andmedium pressure lamps are employed in radiation devices for manyapplications for influencing surfaces, in particular for environmentallysafe hardening or curing of coatings, printing inks and paint. Dependingupon soiling and wear, the lamp must be cleaned at intervals or, as thecase may be, must be changed out. It is also necessary to remove thelamp for access to other component parts which must be serviced, such asreflectors. Thereby appropriate safety procedures must be met, sincesuch UV-lamps are driven by high voltage and warm up to hightemperatures during operation. With conventional connector systems forsuch lamps the voltage conducting connector cables to the lamp bases arematerially joined with the electrode system. The removal of the lampthus requires a work intensive disconnecting and freeing of theconnector cables in the carrier housing under confined conditions. Forthis reason, it is often the case that essential cleaning operations ora necessary lamp change-out is postponed longer than necessary. Inaddition to this, there are safety problems due to metal parts which canbe contacted, which can be subjected to voltage in the case of anaccident during installation of the lamp. Further, it is frequently thecase that such open conductor parts must be kept free relative toconductive housing parts by sufficient insulation areas, which leads toa reduced radiation zone for a given housing dimension.

SUMMARY OF THE INVENTION

Beginning therewith, it is the task of the present invention to providea connector system which overcomes the above mentioned disadvantages andprovides with a compact construction a simple assembly and highoperational safety.

The invention is based upon the concept, of combining a simple mountingfor the lamp with a reliable contact establishment. In accordancetherewith it is proposed that the lamp bases which are respectivelyprovided spaced apart at the connecting ends of the lamp longitudinaldirection are provided with a contact pin connected electrically with alamp electrode as well as an insulation housing surrounding the contactpin on all sides while however keeping open a side or lateral connectoropening, and that the assembled unit includes respectively one contactelement insertable through the connecting opening of the associated lampbase and releaseably contacting with the contact pin, and via connectinglines is energizable with high voltage, as well as an insulating bodywhich carries the contact element and in the connected condition coversover the connection opening. Therewith, the possibility of a rapidreplacement, with good all around insulation in the connected condition,is insured.

A particularly advantageous and reliable contact production is achievedthereby, that the contact pins are insertable and removable withouttools from a slot extending radially perpendicular to the lamplongitudinal axis with production of a clamp connection with the contactelements.

In order to further simplify the insertion or plug-in mechanism, it isproposed that the contact elements are formed by a U-shaped springcontact, of which the spring shanks with their each other facing contactsides are spreadable under spring tension against the contact pin.

A further improvement of the contact production and contact effect canbe achieved thereby, that the spring shanks of the spring contactexhibit an arch-shaped bent contact segment and an end segment bent orangled outwards, away from the contact side which lies flush against thecontact pin over a partial circumference, wherein the gap-width of theinsertion gap bordered by the end segments is smaller than the diameterof the contact pin.

It is also advantageous when the contact element can be anchored to theinsulation body via a connection part which at the same time isconnectable with the connection circuit. In order to insure a completecontact even in the case of deviations in form and position, it isadvantageous when the contact element is mounted “floating” in theinsulation body with free play. This can be accomplished for example bya spring disk formed by a spring element. Preferably, the connectionpart is formed by a core piece provided between the spring shanks of thespring contact and a threaded shaft formed on the core piece extendingthrough the spring contact on its spring shank connecting base.

A particularly preferred shock protection and a secure covering-over ofthe conductive parts is advantageously achieved thereby, that theinsulation body includes a U- or C-shaped support part, on the innerside of which the contact element is provided extending centrally. In amechanically advantageous embodiment it is envisioned that the contactelement is maintained fixed against rotation in a recess of theinsulation body.

For simplification of assembly it is proposed that the insulation bodyexhibits a flange formed at the end side of the support part forsecuring to the lamp housing. Preferably the contact pin in the form ofa hollow cylinder pin is internally contactable with a connection wireof the associated lamp electrode.

In order to facilitate the engagement of the contact element, it isproposed that a ring space is maintained free between the insulationhousing and the therein concentrically provided contact pin.

For centering and supporting it is advantageous when the contact pin, onits end segment facing the discharge lamp, exhibits a radiallyprojecting collar or flange lying against the inside of the insulationhousing.

In order to ensure a sufficient mechanical rigidity or stability, it isadvantageous when the insulation housing includes a support segmentreceiving the connecting end of the discharge lamp, preferably sealedwith a ceramic cement, and a connection opening associated free endformed for mounting the contact pin. Therein it is advantageous when theend of the collar or flange of the contact pin borders the inner spaceof the support segment of the insulation housing.

Advantageously the contact pin is mounted or carried by its free endpreferably formed by a narrowing centering connection projectionsupported in a central recess of an end wall forming the free end of theinsulation housing. The insulating end wall makes it possible todispense with further insulation segments in the lamp longitudinaldirection, so that a compact apparatus design is made possible.

With respect to the mechanical stabilization a further improvement isachieved thereby, that the insulation housing includes a flattened wallpart bordering on the connection opening, extending axially to a lampend side, which in the connected condition comes into alignment with afacing plane surface of the insulation body.

In order to simplify the engagement of the contact element and to keepfree a sufficient contact surface, it is advantageous when theconnection opening viewed in the circumference direction of theinsulation housing of the base exhibits an opening angle of at least120° and in the axial direction of the insulation housing exhibits anopening breadth of at least 5 mm, preferably 10 mm.

Preferably, the insulation housing of the base and the insulation bodyrespectively are comprised of a one-piece shaped part of an electricinsulating, thermally conductive and heat resistant material, preferablya ceramic material.

In order to achieve a low transition or contact resistance and a highdurability or longevity, it is of advantage, when the contact elementand/or the contact pin are comprised of a stainless steel or copper or acopper-beryllium-alloy and in certain cases are coated or plated with anelectrically highly conductive, non-oxidizing surface layer, preferablyof gold or silver.

A further aspect of the invention concerns a discharge lamp, inparticular a mercury discharge lamp or mercury medium discharge lamp foremployment in an UV-radiating device, with sockets on two sides, arod-shaped discharge lamp and an inventive connection device.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in greater detail onthe basis of the illustrative embodiment represented in schematic mannerin the figures. There is shown

FIG. 1 a connection device for one connector end of a discharge lamp ofwhich only one end is shown, in axial vertical section;

FIG. 2 and FIG. 3 a lamp base for the connection device in the end viewand top view;

FIG. 4 and FIG. 5 an assembled representation of the connection devicefor receiving a lamp base in an end view and a top view.

DETAILED DESCRIPTION OF THE INVENTION

The connection device 10 shown in the figure or, as the case may be,connection fitting or mounting, serves for rapid replaceable mountingand for electrical connection of a rod shaped mercury vapor gasdischarge lamp 12 in a housing 14 of a not shown UV-radiating device. Itis comprised of essentially one lamp base 20 provided on the twoconnector ends 16 of the discharge tube 18 of the discharge lamp 12 aswell as respectively one insert socket 22 for receiving the associatedlamp bases or base 20.

The lamp bases 20 respectively exhibit one contact pin 26 projectingaxially at the connector end 16, that is, in the direction of the lamplongitudinal axis 24, as well as a basically cylindrical ceramicinsulating cylinder 28 provided co-axially to the contact pin 26. Thecontact pin 26 is designed as a hollow cylinder pin and is weldedinternally to a connection wire 30 extending out from the connector end,which is in electrical contact, via a metal band piece 32 extendingthrough the glass melt 34, with a coiled pin electrode 36 projectinginto the discharge tube 18. On its lamp end the contact pin 26 exhibitsa radially projecting plate-shaped flange 38, which lies radiallyagainst the inner wall of the insulation housing 20.

The support segment 40, on the lamp-end of the insulation housing of thebase 20, surrounds the connector end 16, and is form-fittingly connectedtherewith via a ceramic cement 42. On its end the connection area isseparated by a flange 38 from a contact pin 26 receiving free endsegment 44 of the insulation housing 20. The end segment 44 is providedwith a lateral connector opening 46 formed by a radial interruption orthrough hole of the housing, which over the remainder however is closedoff on all sides, keeping free a ring space 48 with respect to thecontact pin 26. The connection opening 46 extends over an opening angleof approximately 160° in the circumference direction and has an axialopening breadth of approximately 10 mm. At its free end wall 50 theinsulation housing of the base 20 exhibits a central, inwardly openblind borehole 51, in which the contact pin 26 is supported via acentering connector piece 52 which narrows toward the end. An innershoulder 54 of the insulation housing 20 forms an abutment for thecontact pin 26, wherein the collar or flange 38 thereof is provided forcompensating differential thermal expansions in axial distance from theinner shoulder 54.

The insert socket 22 is comprised of a spring contact which can bebrought into clamping contact with the contact pin 26 and via aconnection cable 56 is chargeable with high voltage (greater than 1 kV)as well as a ceramic insulation body 60 carrying the spring contact 58.As can be best seen from FIG. 4, the U-shaped spring contact 58 exhibitstwo spring shanks 62, which with their each other facing contact sidesare diametrically spreadable upon the contact pin 26. For this purposethe spring shanks 62 respectively exhibit a central segment 64 bent overtheir length conforming to the cross sectional contour of the contactpin, and an end segment 66 angled or bent towards the outside away fromthe contact side. Thereby the narrow width of the insertion gap 68bounded by the end segment 66 is smaller than the diameter of thecontact pin 26, so that the spring contact 58 is easily spreadable andin the connected condition is engageable with the contact pin 26.

The insulation body 60 exhibits a receiving part 70 in the form of aU-shaped profile piece for receiving the lamp base 20 and a flange 72formed on the end face of the receiving part 70 for a screw connectionto the housing 14. The receiving part 70 is internally provided on itscross-piece 74 with a longitudinal groove 76, in which the springcontact 58 is maintained fixed against rotation on its base. Foranchoring the spring contact 58 a core piece 78 is riveted between thespring shanks 62, which via a threaded shaft 80 extends through thecross piece 74 of the receiving part 70 and which on its back side issupported by means of a nut 82 (FIG. 1). On the projecting free end ofthe threaded shaft 80, a threaded socket 84 forming a connector socketfor a connection cable 56 can be screwed on, which for its part in theassembled condition is insulated by a ceramic sleeve nut or cap orbushing 86. In order to further reduce the contact resistance, the corepiece 78 on its contact side 88 lying against the contact pin 26 isformed concave complimentary to the outer contour thereof. Formechanical stabilization, the support segment 40 of the insulatingcylinder 28 exhibits a flattened wall part 90 (FIG. 3) extending axiallyin the connection opening 46, which can be reliably engaged againsttilting with the planar inner surface 92 of the cross piece 74 of thereceiving part 70. A reliable position stabilization is achieved by theshanks of the receiving part 70 which, with their each other facinginner sides, center the sides of the support segment 40 of theinsulating cylinder 28.

The discharge lamp 12 with its lamp base 20 can be assembled to andagain removed in simple manner without tools from the insert sockets 22.Thereby the contact pins 26 are brought into engagement or, as the casemay be, again released from engagement with the spring contacts 58 in ajoining device running transverse to the lamp longitudinal axis 24. Thefree ring space 48 makes possible a corresponding spreading apart of thespring shanks 62. The receiving part 70 of the insulation body 60 coversover in the connected state the connection opening 46 of the insulatingcylinder 28, so that an all side insulation in a safe protection fromcontact is achieved.

1. A connection device for a rod-shaped two-ended discharge lamp (12),in particular a mercury high pressure lamp or mercury medium pressurelamp, with two lamp bases (20) provided at the connector ends (16) ofthe discharge lamp (12) and two insert sockets (22) for receiving thelamp bases (20) mounted spaced apart from each other in a lamp housing(14), wherein the lamp bases (20) respectively exhibit one contact pin(26) extending in the longitudinal direction (24) from the connector end(16) of the lamp, electrically connected with a lamp electrode (36), aswell as an insulating cylinder (28) completely surrounding the contactpin (26) on all sides with the exception of a lateral connection opening(46), and wherein the insert sockets (22) respectively exhibit a contactelement (58) extending through the connection opening (46) of theassociated lamp base (20) which is adapted to be brought into releasableengagement with its contact pin (26), which contact element (58) isenergizable with high voltage via a connection line (56), as well as aninsulation body (60) for carrying the contact element (58) and coveringthe connection opening (46) when in the connected condition.
 2. Theconnection device according to claim 1, wherein the contact pins (26)can be engaged and disengaged without tools in a connecting device whichextends perpendicularly to the lamp longitudinal axis (24), producing aclamp connection with the contact elements (58).
 3. The connectiondevice according to claim 1, wherein the contact elements (58) comprisea U-shaped spring contact, of which the spring shanks (62), with theireach-other facing contact sides, are spreadable providing spring tensionupon the contact pin (26).
 4. The connection device according to claim3, wherein the spring shanks (62) of the spring contact (58) exhibit acontact segment (64) bent into an arc lying flush over a partialcircumference against the contact pin (26), as well as an end segment(66) bent outwardly away from the contact side, wherein the gap width ofthe insertion gap (68) bordered by the end segments (66) is smaller thanthe diameter of the contact pin (26).
 5. The connection device accordingto claim 1, wherein the contact element (58) is anchored onto theinsulation body (60) via a connection part (78, 80) which is connectedat the same time with the connection line (56).
 6. The connection deviceaccording to claim 1, wherein the contact element (58) is mounted at theinsulation body (60) with tolerance or play via a spring element.
 7. Theconnection device according to claim 5, wherein the connection part (78)is formed by a core piece provided between the spring shanks (62) of thespring contact (58) and a threaded shaft (80) formed on the core piece(78) and extending through the base connecting the spring shanks (62) ofthe spring contact (58).
 8. The connection device according to claim 1,wherein the insulation body (60) exhibits a U- or C-shaped receivingpart (70), on the inner side (92) of which the contact element (58) isprovided, spaced apart, centrally.
 9. The connection device according toclaim 1, wherein the contact element (58) is maintained fixed againstrotation in a recess (76) of the insulation body (60).
 10. Theconnection device according to claim 1, wherein the insulation body (60)exhibits a flange (72) formed at the end face of the receiving part (70)for securing to the lamp housing (14).
 11. The connection deviceaccording to claim 1, wherein the hollow cylinder pin-shaped contact pin(26) is adapted for forming an internal contact with the connection wire(30) of the associated lamp electrode (36).
 12. The connection deviceaccording, to claim 1, whereby between the insulating cylinder (28) andthe therein concentrically positioned contact pin (26) a ring space (48)is kept free for engagement of the contact element (58).
 13. Theconnection device according to claim 1, wherein the contact pin (26)exhibits on its end segment facing the discharge lamp (12) a radiallyprojecting flange (38) lying against the inward side of the insulatingcylinder (28).
 14. The connection device according to claim 1, whereinthe insulating cylinder (28) includes a support segment (40) and a freeend segment (44), the support segment (40) adapted for receiving theconnector end (16) of the discharge lamp (12), preferably sealed by aceramic cement (42), and the free end segment (44) provided with alateral connection opening (46) and formed as a mounting for the contactpin (26).
 15. The connection device according to claim 14, wherein theflange (38) of the contact pin (26) borders the end face of the innerspace of the support segment (40) of the insulating cylinder (28). 16.The connection device according to claim 1, wherein the insulatingcylinder (28) exhibits a flattened wall part (90) extending axially toits lamp-end side, bordering the connection opening (46), which in theconnected condition comes into contact with an associated planar surface(92) of the insulation body (60).
 17. The connection device according toclaim 1, wherein the insulating cylinder (28) and the insulation body(60) are respectively comprised of a one piece shaped part of anelectrically insulating, thermally conductive and heat resistantmaterial, preferably a ceramic material.
 18. The connection deviceaccording to claim 1, wherein the contact element (58) and/or thecontact pin (26) are comprised of stainless steel or copper or acopper-beryllium-alloy, and optionally coated with an electricallyhighly conductive, non-oxidating surface layer, preferably gold orsilver.
 19. A connection device for a rod-shaped two-ended dischargelamp (12), in particular a mercury high pressure lamp or mercury mediumpressure lamp, with two lamp bases (20) provided at the connector ends(16) of the discharge lamp (12) and two insert sockets (22) forreceiving the lamp bases (20) mounted spaced apart: from each other in alamp housing (14), wherein the lamp bases (20) respectively exhibit onecontact pin (26) extending in the longitudinal direction (24) from theconnector end (16) of the lamp, electrically connected with a lampelectrode (36), as well as an insulating cylinder (28) completelysurrounding the contact pin (26) on all sides with the exception of alateral connection opening (46), wherein the insert sockets (22)respectively exhibit a contact element (58) extending through theconnection opening (46) of the associated lamp base (20) which isadapted to be brought into releasable engagement with its contact pin(26), which contact element (58) is energizable with high voltage via aconnection line (56), as well as an insulation body (60) for carryingthe contact element (58) and covering the connection opening (46) whenin the connected condition, and wherein the contact pin (26) on its freeend, preferably in the form of a narrowing centering extension (52), ismounted in a central recess (51) of an end wall (50) opposite to the pinforming the free end face of the insulating cylinder (28).
 20. Aconnection device for a rod-shaped two-ended discharge lamp (12), inparticular a mercury high pressure lamp or mercury medium pressure lamp,with two lamp bases (20) provided at the connector ends (16) of thedischarge lamp (12) and two insert sockets (22) for receiving the lampbases (20) mounted spaced apart from each other in a lamp housing (14),wherein the lamp bases (20) respectively exhibit one contact pin (26)extending in the longitudinal direction (24) from the connector end (16)of the lamp, electrically connected with a lamp electrode (36), as wellas an insulating cylinder (28) completely surrounding the contact pin(26) on all sides with the exception of a lateral connection opening(46), wherein the insert sockets (22) respectively exhibit a contactelement (58) extending through the connection opening (46) of theassociated lamp base (20) which is adapted to be brought into releasableengagement with its contact pin (26), which contact element (58) isenergizable with high voltage via a connection line (56), as well as aninsulation body (60) for carrying the contact element (58) and coveringthe connection opening (46) when in the connected condition, and whereinthe connection opening (46) exhibits an opening angle of at least 120°viewed in the circumference direction of the insulating cylinder (28)and in the axial direction of the insulating cylinder (28) exhibits anopening breadth of at least 5 mm.
 21. A mercury-high-pressure lamp ormercury-medium-pressure lamp for employment in a UV-radiating device,with a rod-shaped discharge lamp (18) having connector ends on bothsides, whereby a connection device (10) with two lamp bases (20)provided at the connector ends (16) of the discharge lamp (12) and twoinsert sockets (22) for receiving the lamp bases (20) mounted spacedapart from each other in a lamp housing (14), thereby characterized,that the lamp bases (20) respectively exhibit one contact pin (26)extending in the longitudinal direction (24) from the connector end (16)of the lamp, electrically connected with a lamp electrode (36), as wellas an insulating cylinder (28) completely surrounding the contact pin(26) on all sides with the exception of a lateral connection opening(46), and that the insert sockets (22) respectively exhibit a contactelement (58) extending through the connection opening (46) of theassociated lamp base (20) which is adapted to be brought into releasableengagement with its contact pin (26), which contact element (58) isenergizable with high voltage via a connection line (56), as well as aninsulation body (60) for carrying the contact element (58) and coveringthe connection opening (46) when in the connected condition.